FIG. 1A and FIG. 1B are cross-sections illustrating a conventional drive mechanism 100 having the functions of auto-deceleration and self-locking. Referring to both FIG. 1A and FIG. 1B, a rotating housing 102 may force three inside acceleration gear assemblies 104a, 104b and 104c to rotate and thus enable a centrifugal brake shoe 106 to rotate at a high speed. When the centrifugal brake shoe 106 rotates in a rotation direction R at a high speed, the centrifugal brake shoe 106 also naturally moves outwards in a direction S to rub against the housing 102 to fulfill auto-deceleration. Further, when the housing 102 ceases rotating, the centrifugal brake shoe 106 also ceases rotating and returns to the center due to the gravity force. Hence, the gear tooth of a metal fixed gear 110 hangs on a hook 108 of the centrifugal brake shoe 106 to fulfill self-locking.